Disclosed herein is a carrier bead collection assembly for a xerographic printer.
Carrier Beads are coarse, granular particles that along with a finely-divided, pigmented, powder referred to as toner, make up a developer mixture in a xerographic printer. The carrier beads are made or are coated with a material which is removed from the toner material in the triboelectric series so that when the two are mixed together to form the developer mixture, the toner particles are triboelectrically attracted to the carrier beads. The toner particles are small relative to the carrier beads and many toner particles are “carried” throughout the development system by each carrier bead.
As carrier beads fall into the paper path of a xerographic printer, they become attracted to the steel sheet metal parts in the paper transportation mechanism and may remain in place on the sheet metal for indefinite amounts of time. The carrier beads are made of steel or ferrite, are small in size, are typically less than 150 microns in diameter, and have irregular jagged surfaces. When the carrier beads remain on the paper transport, they scratch media sheets passing over them. For simplex runs, the backside of the print (unprinted) is damaged, whereas for duplex runs, the printed side 1 image is damaged, leaving obvious fine line scratch defects.
Sometimes the carrier beads are dragged or carried away by the media sheets; and sometimes they stay on the steel surface for long periods of time resulting in hundreds of defective prints. The problem has been temporarily amended by cleaning the surfaces of the steel transports after scratches are observed. This method is unreliable, temporary, and only addresses the problem after one or more media sheets have been damaged.